Multirural semiautomatic telephone exchange system



5N r J MULTIRURAL SEMI-AUTOMATIG TELEPHONE EXCHANGE SYSTEM Filed July23, 1945 5 SheecS Sheet l I (.7/ M AGENT F. P. GOHOREL Dec. 30, 1947.

MULTIRURAL SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM Filed July 25, 19455 Sheets-Sheet 2 INVENTOR FIR/Wino RGGIIOIPKL W AGE Dec. 30, 1947.GOHOREL 2,433,359

MULTIRURAL SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM Filed July 23, 19455 Sheets-Sheet 3 i dsla/ 7?) SUBSEQUE/VT FIND-5R6 AGEN Dec. 30, 1947. F.P. GOHOREL MULTIRURAL SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM FiledJuly 25, 1943 5 Sheets-Sheet 4 INVENTOR Ff/P/V/I/V/J P. 60/1/0199 Dec.30, 1947. F. P. GOHOREL MULTIRURAL SEMI-AUTOMATIC TELEPHONE EXCHANGESYSTEM Filed July 23, 1945 ,5 Sheets-Sheet 5 soooaooooo o n 00 n u onvan 0 v o u a we a o u 0 00000 c on a O INVENTOR FE/PNfl/VD I? Gal/06 :1

AGENT Patented Dec. 30, 1947 MULTIRURAL SEMIAUTOMATIC TELE- PHONEEXCHANGE SYSTEM Fernand P. Gohorel, Sceaux, France, assignor toInternational Standard Electric Corporation, New York, N. Y., acorporation of Delaware Application July 23, 1943, Serial No. 495,847 InFrance May 13, 1941 11 Claims. (Cl. 179-27) 1 The present inventionrelates to semi-automatic telephone systems and more particularly tosystems including rural exchanges in which the establishment ofconnections is controlled by a distant operator located at a manualcentral office to which the rural network or district is connected, Thevarious rural networks of a district are connected to the manualcentral, either directly or indirectly, via one or more rural switches.

In known rural systems, the number of digits of the called subscribersnumbers vary, depending on the position of the switch in the rural groupto which the subscriber is connected and on the capacity of the switch.The central operator must know over which circuits the differentsubscribers may be reached, as well as the numbers that must be added tothe subscribers regular number, which are needed for operating All thisslows downthe operation of a rural district and often necestheintermediate switches.

sitates additional operators for handling the traffic of the district.

One object of the present invention is to provide translators forsending the trains of impulses necessary for the intermediate selectingoperations to select the rural area of the called subscriber asdetermined by the first digit or digits of the called number. Thus, thesubscribers lines of a rural district may be uniformly num- According toanother feature of this invention, when the operator is connected with acalling subscriber by a finder, she rings the called subscriber over aninter-rural connection jack. If the called subscriber belongs to thesame rural area as the calling subscriber, then the selector is not usedand the translator impulses are sent over the rural line via apre-selector connected with the inter-network jack and the finder tha isalready in contact with the said line.

In one embodiment of this invention, the translator registers the digitswhich cause the sending of the series of impulses controlling theintermediate switches and at least partially the switch to which thecalled subscriber is connected. The connection may be completed bysending one or more trains of impulses that are registered but-nottranslated. Since the number of impulses sent by the translator dependson the position of the subscriber in the district and on the capacity ofthe switch to which he is connected, arrangements are made that numbersthat correspond to certain positions of the translator be absorbed andnot sent by the translator.

According to another embodiment of this invention, the operator manuallyselects the rural area of the called subscriber according to the firstdigit or digits of the called number, The impulses for eiiecting theselections in the intermediate centrals are sent by a translator set inaccordance with one or more digits of the called number dialed by theoperator. The complete or partial control of the switch to which thecalled subscriber is connected, is effected by the operator when dialingthe last digit or digits of the called number.

Various other features will be set forth in the following descriptionand claims.

In the drawings:

Fig. 1 shows a diagram of the connections of the different pieces ofequipment in the manual central in the case when the selection of thecircuits is effected automatically after dialing of the subscribers callnumber by the operator;

Fig. 2 is the connection arrangement of an outgoing selector such as Sin Fig. 1, shown schematically;

Fig. 3 is the connection arrangement of incoming equipment such as C inFig. 1, shown schematically;

Fig. 4 is the connection arrangement of 'a translator such as E of Fig.1, shown schematically;

Fig. 5 shows the manner in which the various figures 2 to 4 are to beconnected with one another; and

Fig. 6 is the connection diagram of a translator fused in the case whenthe selection of the outgoing circuit is made by the operator accordingto the indication of the first calling figure or 'figures of thesubscriber.

In the following specification, the relay contacts that are closed whenthe relay is energized, i. e. in operating position, are indicated withthe letter T in front of the number of the spring,

and the contacts that are closed when the relay is not energizedfi. e.in the resting position, with the letter R in front of the number of thespring. Furthermore, certain rotary switches have been arranged to usell-direction switches. .These switches are provided with a certainnumher of wipers which are arranged in such a way as to come intocontact with their banks during one or more quarter turns; the quarterturns for which a wiper is in engagement with its bank are indicated byRoman numerals after the reference indication for the wiper.

Referring to Fig. 1, an explanation will first be given of the generalmode of operation of one of the devices according to the invention,which makes it possible to give all the subscribers in the ruraldistrict call code numbers that comprise the same number of figures, theselection of the circuits that correspond to the subscriber's area aswell as the different selections via the switches being effectedauomatically.

Two groups of lines are used. One of them is multiplied on the callingjacks such as G and the other on the inter-rural paired answering andconnection jacks L and L.

Each of the lines G comprises a multipled jack in association with thebusy lamp L01 and connected to a selector S; the rural mixed and specialoutgoing circuits such as ER and ER. are multipled on the banks of theselector. The translators such as E, which serve at the same time ascontrol switches ,for the selectors, are connected to the said selectorsduring the time of selection.

Each of the line assemblies LL' comprises two multipled paired jacks,.one of them being connected to a finder C that has access to the mixedrural circuits such as .ER and to a preselector P which has access tothe selectors S, while the other is connected to a preselector P whichhas access to the same selectors S. A calling lamp LA is associated withthe jack L and a busy lamp L02 is associated with the jack L,

When a rural subscriber makes a .call, he turns the magneto of his setor sends any other suitable calling signal, and his call is registeredin the rural switch to which he is-connected. When the connectioncircuits with the district central, 1. e. the manual exchange, becomestree, the cal1- ing line is connected to the said district central viathe equipment ER. A free finder such as C hunts for the callin circuitand, when this hunting is finished, the calling lamps such as LA lightup in front of the operators. One of them re- .plies by inserting ananswering plug of a twostrand cord in the jack L; the calling lamp LAthen extinguishes and the busy lamp L02 lights up. If the callingsubscriber has not hung up after ringing, the supervisory lamp of thecord circuit extinguishes .and the operator notes the requiredcommunication. If the calling subscriber has hung up, he is rungautomatically and the supervisory lamp flashes and then extinguisheswhen the subscriber replies.

When the plug of the cord circuit is withdrawn :from the lack L. the cnnections-5 released.

In case the communication is intended for a vsubscriber who is connectedto the manual can. tral and who can be reached directly, th op ra torroceeds to test the called line and completes the communication in theusual way In the case where the communication is intended for asubscriber or ,thesame rural district as the calling subscriber, theoperator does no have to bother about knowing whether the calledsubscriber does or does not belong :to the same rural area as thecalling subscriber.

The operator insertsthe secondplug of the twostrand cord into the jack'L" and thus, via a p16- selector such as 'P', seizes :a selector suchas 4 which is associated with a translator or register such as E.

The dial lamp lights up and the operator sets up on her dial the numberof the called subscriber. The translator E registers the combination ofnumbers, translates it and directs the selector S to connect the firstcircuit of the group of circuits that are in connection with the calledrural area.

If the circuit does not belong to the same group as the calling circuit(communication between subscribers of two different rural areas), theselector hunts for a free circuit among the circuits of the called groupand the translator sends back the figures necessary for making theselection .among the various rural switches that are passed over.

On termination of the'selection, the supervisory signals at theoperators position, the ringing of the wanted subscriber and the releaseupon termination of the call are effected by any suitable one of thewell known methods.

If the circuit to which the selector S is directed belongs to the samegroup as the calling circuit (local or intra-area communication) thetranslator E sends back the figures required for the selection in thereverse direction to the calling circuit. via the preselector P and thefinder C. When the selection is finished, the selector S and thetranslator E are released, and the communication between the twosubscribers is established under the conditions usual for a local callbetween rural subscribers. When the communication is established, theoperator withdraws the plugs of the cord circuit and this effects therelease of the finder C and of the circuits not used by the local call.The release upon termination of the call is effected by any well knownmethod.

In case the calling subscriber has hung up after having made his call,the operator calls back the subscriber by inserting the answering plugof a cord circuit in a free jack L and thus connects herself by means ofthe pre-selector P, which is associated with the jack L, to a freeselector S and translator E. She thus puts herself in communication withthe calling subscriber who tells her the number of the calledsubscriber.

The operator then rings the called subscriber by inserting the callingplug of the same cord circuit in the jack L which is paired with thejack L. She thus connects herself via the preselector P that isassociated with the jack L to another free selector S and register E,and this register may be the same as the one that served ,forestablishing the connection with the calling party. The operator sets upthe called subscriber's number and, if the subscriber belongs to adifferent rural area from that of the calling party, the communicationis established via the selectors S, the pre-selectors P and P and thecord circuit.

If the called subscriber and the calling subscriber are connected to oneand the same area, the second selector S directs itself over the samegroup of lines as the first selector and the register .E repeats backthe trains of impulses via the preselector P, the pre-selector P and thefirst selector to the circuit by which the calling subscriber has beenreached.

Calls proceeding from outside subscribers or from other districts arerouted by using a jack G.

The mode of operation of the device will now be explained in detail withreference to Figs. 2, 3 and 4. The equipment of the rural circuit ER hasnot been shown because the details of its operation are not necessaryfor the understanding of the invention.

Call by a rural subscriber.-When a call by a rural subscriber such as Ais registered, by known method, on the equipment ER of a rural circuit,a battery is connected to the wire X, and this causes excitation of therelay I via RiIl. At TI2' relay I completes over R2I the circuit of theelectromagnet RC. The call finder 0 starts out and proceeds to hunt forthe calling circuit. When the wipers of the said finder reach the bankcontacts of the equipment ER, the following circuit of relay 2 iscompleted: battery connected to the equipment ER, over the wire 1* tothe receiving end of the call, bank contact and wiper R, the windings,in series, of relay 2, TI3 and earth.

Relay 2 comes into the holding position and opens at R2I the circuit ofthe electromagnet RC. Accordingly the finder C stops at the desiredposition.

At T23 relay 2 completes the circuit of the calling lamp LA, whichlights up. At T2I it completes the circuit of its own low resistancebottom windingand thus denotes the occupation of the circuit.

When the operator inserts the answering plug of a cord circuit into thejack L, a battery is connected to the sleeve of plug CL and completesthe following circuit of relay 6: battery on CL, R13, R64, T22, bottomwinding of relay 6 and earth. At T65 and T66 the said relay 3 connectsthe springs NL and TL of the jack L to the conductors a and b of theequipment ER via the wipers A and B of C. V

The equipment ER then assumes the ringing position if the callingsubscriber has hung up, or it passes to the talking position if he hasheld the line, and the connection is established with the operator whomakes a note of the called subscribers number and then proceeds to callback the calling subscriber and to ring the called subscriber, as willbe explained, further on.

As soon as it is energized, relay 6 has completed at T63 the circuit ofthe upper winding of relay II which pulls up, and at TESI relay 6completes its holding circuit by its upper winding because of the earthapplied to the wire it in the equipment ER, while at T64 it returns thecircuit of the sleeve of plug CL over the wire S. Relay II, which haspulled up, returns at TI II the starting wire to the next finder, and atRI II it opens the circuit of relay I which falls back, thus causing therelease of relay 2. At TI I2 relay I I completes the circuit of the busylamp L02 which lights up.

Establishment of a call between two subscribers of the ruraldistrict-The operator first calls back the calling subscriber. To dothis, she inserts the answering plug of a cord circuit into a free jackL. The following circuit of relay II! is complete: battery applied tothe sleeve of the jack L by the plug, R13, R54, R22, RI2I', winding ofIO and earth.

Relay I8 pulls up and at Tilli it completes the circuit of the upperwinding of relay II which pulls up and causes the lighting up of thebusy lamp and the return to the starting wire. At TIil3 relay I0completes the circuit of the rotary electromagnet R2 of the pre-selectorP via R9I and RI23.

The wipers of P advance in free rotation hunting for a free selectorwhich will be assumed to be that of Fig. 2.

As has been'shown in Fig. 1, a certain number of selectors like that ofFig. 2 are associated with a, register like that of Fig. 4. When theregister is free, relays I3 and I5 in each of the selectors will be inthe holding position. The holding circuit of relay I3 is as follows:ground, winding of I3, RI42, RII2', wire 0, R33I, bank contacts andwiper b of the switch X3 in the resting position, bank contacts andwiper b of the switch :02 in the resting position, bank contacts andwiper a of switch .125 in the resting position, bank contacts and wipera of switch $4 in the resting position, resistance RI and battery. Thecircuit of relay I5 is completed at TI3I. At RI5I relay I5 opens thecircuit of the busy lamp L01.

When the wipers of P reach their free selector, the following circuit ofrelay 9 is completed: ground, TI02, windings of relay 9 in series witheach other, wiper T1 of P, bank contact of the free selector wire t1,upper winding of relay I4, RII2' and battery on the wire 0 over thepreviously mentioned circuit.

Relay 9 pulls up and opens at R9I the circuit of the electromagnet R2.The wipers of P stop at the desired position. At T92 relay 9short-circuits its high resistance bottom windings and at T9I itcompletes the circuit of the bottom winding of relay I2 which comes intothe holding position. At TI22' and TI23 relay I2 returns the talkingconductors to the selector, at RI23 it makes a second cut-01f in thecircuit of the electromagnet R2, at T I 24 it applies a ground to theholding wire, and at TI:2 I it returns the wire of the sleeve CL of theplug to the wiper S1. The battery CL con nected to the Wiper completesvia RII3 the circuit of the bottom winding of relay I8 which pulls upand connects the selector of Fig. 2 to the register of Fig. 4. Moreover,relay I4 becomes energized over the circuit of the test wire t and itdisconnects the selector from the multipling circuits in the directionof the outgoing jacks such as G. At RI42 it opens the circuit of I3which falls back and causes I5 to drop due to the circuit opening at I3IThe circuit of the busy lamp L01 is completed at RI5I.

The battery of the sleeve CL of jack L completes the following circuitof relay 33: battery on CL, R13, R64, R22, TI2I, wiper S1 of P, Wire s1,TI43, RIB3, TI82, wire se, both windings of 33 and earth.

Relay 33 comes into the holding position and completes the followingcircuit of relay 32; ground, winding of 32, T33 I non-inductive upperwinding of 34 and battery. Relay 32 pulls up and via T325 itshort-circuits the high resistance bottom winding of relay 33 via R24Iand R255, and this results in bringing the supervisory relay into theholding position and accordingly causing the lighting up of thesupervisory lamp of the cord circuit.

The operator is thus notified that she can proceed to dial thesubscribers code digits and she depresses her dial key. One result ofthis manipulation is the connecting of the impulse circuit of theoperator's dial to the plug conductor that is connected to the springandthe following circuit of relay 3i: battery, on spring NL, R'II, TIZZ',wiper A1 of P, wire an, RBI, TIBI', wire ac, winding of relay 3|, andground. Relay 3| comes into the holding position and at TSII it closes anew circuit for the relay 32; ground, winding of 32, R33I, T3II,non-indicating upper winding of 34 and battery. By its various contacts,relay 32 prepares the registers operating circuit, and at T323 it placesan earth in. engagement;

Manipulation ofrthe; dial key; has-furthermore had the effect ofshortrcircuitingin the cord cir.- quit the battery that had, beenapplied on the; plugs sleeve CL and this, causes the'release of relay 33of'the register.

At T322 relay 32' (Fig. 4-) completes the circuit ofrelay 38 over thewire 71. and TlB-l to the upper windingofrelay I8; Relay 38- pulls' upandcompletes the circuit of the electromagnet of switch X4": ground,T382, wiper C of X4-at the resting position, contact and electromagnetX4, battery.

The switch X4passes to the first Working position. As soon asthe wiper.a has-left its resting position, the circuit of the abovementioned test.wire;- isopened. All the relays l3 and !5..oi the selectors associatedwith the register fall back and at Rll the circuit of.the-busy lampssuch as L01 is completed;

Since relay 3| is energized, thecirc-uit of X4 is completed'by: ground,T3l2, wiper; C at' the first working position, contact and-electromagnetX4- and battery. The wipers-of X4 pass-.to the second working position.

The operator. will now proceedto. dial the code. digits of the calledsubscriber. It. will be. as-- sumed, for example, that allthesubscribers oi the rural district have a four figure call number. Theoperator proceeds to dial the first figure. The manipulation of thecalling dial causes cutoils" on thebattery connected to the spring NLof- L.

Relay 3! of the. register. will then. follow the impulses emittedbytheoperators dial. Upon each dropping of relay 3|, the following circuit iscompleted: ground, R3l2, T324, w-ipera of X4. at the. second workingposition, electromagnet X5. and. battery. The. wipers of. the switch X5,Will then advanceby as many-steps as there are impulses receiving onrelay 3|.

At the first dropping of. relay 3!, the following circuit of relay 34 iscompleted: battery, series, windings of. 34, T32I, R33l, R3-H andvground. This relay 3| pulls up and holds up during the receiving of atrain of.impulses,-owing to the fact that it is retardedbythe-short-circuiting of its bottom. winding over a circuit including:right hand-terminal of the winding, T3, R331, T32iand left hand outletof the winding.

When relay 34 has pulled up, it completes the circuit of theelectromagnet X4 via T345 across the wiper c. This electromagnetattracts its armature. Upon termination of the receipt of the train ofimpulses, relay 34' falls back and opens at T345 the circuit of theelectromagnet which releases its armature. The wipers of X4 pass to thethird working position. It has been assumed, for example, that thecapacity of the rural district is limited to 2,00.0.-subscriber lines.

The first of the figuresreceived on theregister will determine on whichof the wipers b or d of theswitch X5 thesecondgfigure will beregistered,i; e. will effect the selection of the. thousand digit, in which. thecalledsubscribers line. is. For ex ample, according to the-connections.shown in the drawings for the bank contacts. associated. with the wipera, if thefirst figure is 8, the following circuit of X4 is. completedwhen the Wipers. of the. switch pass to they third working position.after relay 34 falls back: ground, T382, wiper a of X4. at thethirdtWorkin-g position, bank contacts and wiper a of: X5 at the eighthworking position, wiper c of X4 at the third: working position. contactand e1ectromagnetX4 andbattery.

Theelectromagnet X4'makes the wipers pass to.

the fourth working position.

If; the first figure received had been 9, the ground of the wiper a ofX5 would have completed the circuit of relay 31 which would havepulledup. At T31! relay 3'! closes its holding contact, on the ground ofT382, at T312 it puts into service. the Wiper d of X5, and at T313 itcloses the circuitof the electromagnet X4 which makes its Wipers pass tothe fourth Working position.

When the wipers of.- X4 reach the fourth work'- ing position, thefollowing circuit is completed: ground, T382, wiper a of- X4, banksegments and wiper C of X5, contact and electromagnet X5 and battery.The. wipers of X5 advance in free rotation and pass into. the restingposition that corresponds to the second quarter turn.

Wipers e, d, b are engaged and wipers a and. c are disengaged. Thefollowing circuit of the elec-. tromagnet X4 is completed: ground, T382,wiperd of X5 at the resting position, wiper c of X4 at the fourthworking position, Contact and electromagnet X4 and battery.

The electromagnet X4 makes its wipers pass to the fifth Workingposition.

The second train of impulses will be received on. the electromagnet X5via: ground, R3! 2, T324, wiper a of X4 at the fifth position.electromagnet X5 and battery.

The wipers b, d and e of X5 will advance on. their bank contact by avnumber of. steps equal to the figure received.

Upon termination of the receipt of the second train of impulses, theelectromagnet X4 which had attracted its armature when relay 34 pulledup, releases it when T345 is opened and the wipers of the switchX passto the. sixth working position.

The third train of impulses is then received on the electromagnet X2which advances its wipers by a number of steps corresponding to thenumber of impulses received.

When relay 34 falls back, the electromagnet X4 advances its wipers tothe seventh working position. The following circuit of the electromagnetX3 is then completed: ground, T382, wiper a of X4 at the seventhposition, wiper a of X3 at the resting position, contact andelectromagnet X3 and battery.

The electromagnet X3 moves its wipers to the first working position. Thefollowing circuit of the electromagnet X4 is completed: ground, T382,wiper b of" X3 at the first working position, wiper C of X4 at theseventh working position, contact and electromagnet of' X4 and battery.The electromagnet X4 moves its wipers to the eighth position and thenadvances via the ground placed on the bank contacts to the restingposition that corresponds tothe second quarter turn.

Wipers a and c are disengaged, and the other wipers are engaged.

Thefourth figure is then received on. the switch X4 over:- ground, R3l2,T324, Wiper d and bank contact for the, first figure, T342, Wiper d andbank contacts for the next figures. The switch X4 will advance itswipers during the 2d quarter turnby a number of steps equal to thenumber of impulses received.

An explanation will, now be given of how the translator TR is controlledand how the impulses are repeated back by the register. When the wipersof switch X3 are at the first working position, the following circuit ofthe electromagnet RD of the translator TB is completed: ground, R2! I,wiper d of X3 at the first working position, contact and electromagnetRD and battery.

It will be noted that at the banks of contacts of th switch oftranslator TR it has been assumed that each bank contacts of the wipersb and d of X4 has been multipled on five bank contacts. For the total often bank contacts of the wipers b and d of X there will accordingly beone hundred contacts on the switch of the translator. Only some of thesecontacts are shown in the drawings. Moreover, for each position of thetranslators switch, the marking wipers (e, f, g and it) have access, bymeans of the distribution frame Re and the relay set C, to twentymarking positions on the switch X, and this gives for the total 100contacts of the said translator switch the marking positions for the2,000 or less subscribers for whom it is assumed to be arranged.

The switch wipers advance, since the circuit of the electromagnet RD isclosed, as mentioned.

When the Wipers a, b of RD reach the contact carrying members thatcorrespond to th combination of the first three digits registered, thefollowing circuit of relay 2| is completed: ground, series windings ofrelay 2|, wiper a of X2 at the position to which it has been brought bythe third train of impulses, bank contact associated with the wiper b ofRD, wiper a and, for example, bank contact of the wiper b of X5 to whichthe said wiper has been brought by the second train of impulses, wiperb, R312, resistance R2 and battery.

Relay 2| pulls up and opens at R2| the circuit of the electromagnet RD.The wipers of the translator stop at the desired position, and thisposition depends on the first three impulses receiving on the register.

At T2|| relay 2| forms the circuit of the electromagnet X3 over thewiper a at the first Working position. This electromagnet advances theswitch wipers to the second working position. At the latter position,the circuit of relay 2| is opened at the wiper C; the said relay fallsback and completes the circuit of the electromagnet X3 over the wiper aat the second working position. The

wipers of X3 pass to the third working position.

The starting circuit of the selector of Fig. 2 is completed over:ground, R2l I (Fig. 4), wiper d at the third working position, wire 1,Tl86, RI'H, contact and electromagnet R and battery.

The electromagnet R will advance the wipers of the selector S in freerotation in order to proceed with the control of the selector to thegroup of lines of the rural area that corresponds to stopped, controlwire FC, wiper C1 of selector S,

H83, wire C, resistance R2 and battery. Relay 2| pulls up and opens atR2|| the circuit of the electromagnet R of S. The wipers of the said,

selector stop at the free line associated with a rural equipment such asER.

In the example shown in'the drawings, if the third digit registered isan even number 0, 2, 4, 6, or 8, the following circuit of relay C of thetranslator is completed: battery, winding of relay C, wiper b of X2 atan even number position, wiper b of X3 at the third working position,T382 and ground. Relay C pulls up.

When relay 2| has pulled up, it has completed at T2 the circuit of theelectromagnet X3 which advances its wipers to the fourth workingposition or position of discrimination.

. The following circuit of relay 22 is completed:

battery, common relay D, series windings of relay 22, wiper b of X3 atthe 4th working position. T382 and ground. If there is no other registerin a position of discrimination (position 4 of a switch X3), relay 22becomes energized and short-circuits its high resistance upper windingin order to make impossible the energization of relay 22 of anotherregister coming into the position of discrimination. At T224 itcompletes the circuit of relay 24: battery, winding of 24, R262, T224,R2 and ground; at T223 it connects the wire (I to the upper winding ofrelay 25 and connects a ground in series with the resistance R3 on thewire d. In the case under consideration, the circuits of wires (1 and ddo not enter into action.

Relay 24 becomes energized and pulls up and at T246 it completes thefollowing circuit of relay 2|: ground, windings of relay 2|, T246, wireit, T|84, RI'I5, wiper T of S, wire t and battery connected to the wiret in the rural equipment ER. The relay 2| pulls up.

At T243 relay 24 completes via the wiper a of X3 at the fourth workingposition the circuits of the electromagnet X3 which becomes energizedand advances its wipers to the fifth working position.

At this position the circuit of relay ll of the selector is completed:ground, T2||, wiper b of X3 at the fifth position, wire 1, Tl83, windingof relay I! and battery.

At R|15 relay l'l opens the circuit of relay 2| which falls back. Thefollowing circuit of relay 25 of the register is completed: battery,upper winding of 25, wiper C of X3 at the fifth working position, wiress, Tl8l, TI'H, Wiper s of selector S, wire s and ground applied on thewire s in the rural equipment ER.

When relay 2| has fallen back, the advance circuit of switch X3 iscompleted: ground, R2| T255, wiper a at the fifth working position,electromagnet X3 and battery. The wipers of X3 pass into the sixthworking position. For this position the battery connected over the wiperC is suppressed on the wire es and consequently on the wire s thatterminates at the rural equipment, and this results in passing theequipment into dialing position.

The battery over relay 23 is shunted by the wiper b of XI, which is inresting position, with the battery over the springs of impulses I2 andresistance R5. When the ground in the rural equipment ER is applied tothe wire a to indicate that the equipment is ready to receive thedialing impulses, the ground is received over TI" and TI82 on the wireas, and Over T245 the wiper C of X3 at the sixth position energizes therelay 23 when the cam I2 opens its contact.

The wiper b of X3 at the sixth position connects a battery to the wipera of TR over the resistance R6.

The four wipers e, f, y and h control the sending of the trains ofimpulses. In the example shown in thedrawings it can be seen that thefirst three digits of the registered number can effect the control ofthe selector connected to the register, and also the sending of fourtrains of impulses, i. e. five selections in all. In case one or moretrains of impulses are not to be sent, the bank contacts that correspondto the wipers e, f, g, h are connected at Re to the terminal Y and thiscauses the advance of the corresponding positions by the electromagnetX3.

When relay 23becomes energized upon the opening of the impulse springsI2, it closes the cirsent over the circuit via: battery, resistance Rimpulse springs 12, wiper c of X3, T245, wire as, TI82, TI'I4, wiper Aof S, wire a and impulse relay of the equipment ER.

u Theswitch XI advances under the action of the impulses emitted by theimpulse springs I1 over the circuit: ground, springs I T381, R2I4, RI,wiper c of XI, electromagnet XI and bat- When the wipers of XI haveadvanced by the :number of steps that correspond to the number ofimpulses to be sent, which is determined by the connection made on thedistribution frame Re of TR, the following circuit of relay 25 iscompleted: ground, bottom winding of 25, wiper a of XI, bank contact towhich there is connected in Re the wire that belongs tothe contact ofthe wiper e on which the wiper has stopped, distribution frame Re, bankcontact and wiper e of RD, wiper b of X3 at the sixth working position,resistance R6 and battery. I

Relay 25 pulls up and at T252 it short-circuits the impulse springs 12and this stops the sending of the impulses over the line equipment. AtT253 ,it closes its holding circuit over the resistance 34, andat T25Iit completes the automatic rotation circuit of XI: battery,electromagnet XI, wiper c of X1, wiper d of X1, T25I, interruptor springof X1 and ground. The switch X1 thus advances in free rotation as far asits sixteenth position, In order to retard its return to the restingposition, the advance to the last positions is controlled by the ,cam I1over the circuit: battery, electromagnet X1, bank and wiper d of X1,T331, impulse springs I and ground; and for the last 1 bank contact butone over; bank and wiper d of 3. T 1. im l e pr I, and nd. When theswitch XI has returned to its resting position, the wipers'shortcircuits the relay 2 5 which falls back, and relay 23 is againconnected to the wire as over the wiper c OfXl at its restingposition. rv H p v During the passage of the wiper o of XI a ground impulse is sentto the electromagnet X3 over the circuit: ground, spring contacts I1,T381,

wiper b of XI at the last position, R2I3, wiper a of X3 at the sixthposition, electromagnet X3'a'nd'" I battery. The wipers of X3 pass tothe seventh working position for which the battery over the resistanceR6 is applied to the Wiper J of the translator TR.

The above indicated procedure isrepeated for each train of impulseswhose sending is caused by the ground applied to the wire as from therural equipment ER, the ground effecting the energization of relay 23,as has been explained. The

stoppage of the sending of the impulses is ef-' fected, as shown for thefirst digit, when the wiper a of XI reaches the bank contact to which isconnected the wipers f, g, or h of TR that controls the emitted impulse.

, As has been shown, some of the registered digits may not be repeatedback by'the translator. In

this case, the bank contacts'of the'wipers' e, f, g, it that correspondto the said figures are concts ie th i m a iqfli are when the H ers ofX3 reach the corresponding" position, the

Eircuit of relay 2I is completed over the wiper b of X3, the resistanceR6 "and the battery. Relay 2I pulls up and'opens at RZ'I 4the advancecircuit of switch XI, and at T2 I3 it springs I1, T361, T2I3, wiper a ofX3, "electromognet X3 and battery. The electromagnet X3 advances itswipers to the next position.

If, for example, it is assumed that each position of the translatorcorresponds to a group of 26 subscribers, i. e. two of 10: 00 to 19, 20to 39, etc., the wire controlling these'nding of the tens impulsesshould'be connectable to two difierent contacts in the bank of senderXI. Thus for the tens beginningwith 0 and 1, this wire is connected tothe second contact of the wiper a of XI for the tens beginning with 1,and to the'tenth contact for the tens beginning with 0, and to thecontacts 3 and 4, etc.,'for thete'ns beginning with 2 and 3, etc. Thisswitching to one contact or the other is effected by the relay C of TR,the operation of which has been explained for the fourth workingposition of the switch X3,

When all the trains ofimpulses that have been determined by' theposition of the translator TR have been sent, the switch X3 will havebrought its wipers to the tenth working position. The sending of theimpulses of the units whose number is determined by the received digitthat has been registered on the switch X4 will now take place. Thebattery over the resistance'R5, the

wiper b of X3 and the wiper 1:: of X4, is connected to the control wirethat corresponds to the registered number, the control wirebeingco'nnected to the contact that corresponds to the bank of wiper aof the switch XI. The sending of the impulses accordingly takes place inthe already described manner.

When the wipers of the switch XI reach the last contact but one of thebank, after the sending of the unit digit, they stop, since the advancecircuit is open on the wiper d of the switch X3. Relay 32 isshort-circuited by the circuit: ground, wiper b of XI at the ninthworking position, wiper a of X3 at the tenth working position, left handterminalof the winding of relay 32. The relay falls back and-opens atT322 the circuit of the relays 38 of the register and I8 of theselector, which fall back.

The circuit of relay 36 is'completedzg'round, bottom winding of 36,R38I, segments and wiper ,f of X4, contactand ele'ctromagnet X4 andbattery. Relay 36 pulls up and at T364 it completes the return to restcircuits of the switches X4, X5,

X2 and X3. V

The'circuit of X4i's: ground, T364, REBI, segments' and wiper f, contactand electromagnet X4 and battery. This circuit 'is' opened when theswitch X4 has returned to its resting'position.

Circuit of X5: battery, electrom'agnet'X5, segments and wipers C or 6according to the position of the 'switch, R384, T364, and ground.

Circuit of X2: battery,"electromagnet X2, segments and wiper C, R336,T364 and ou Circuit of X3 :"battery, elec'tromagnet X3, wiper gases, T364 and ground.

When these various switches have ret'urned'to the resting position,the'following short-circuiting fcircuit of relay 36 is completed:ground, T363,

T36I, wiper b of "X3 atits resting position, wiper b of X2 at itsresting position, wiper a of X5 at its r'esting position, wiper a ofX4at its resting'position, right hand outlet of the upper winding ofrelay'36. Relay 36 falls back and closes at V36I the engagement circuitof the register.

Upon the falling back'of relay 38, the switch XI will have cleared theninth workingposition via the circuit: ground, contact of theelectromagnet XI, R388, wiper b at the ninth position, electromagnet XIand battery. The tenth position is cleared by the circuit: ground,contact of XI, R361, wiper b at the tenth position, electromagnet X andbattery. The switch XI returns to the resting position. When relay I8has fallen back, since its circuit is open at R323 of the register, itwill have cut on? the connections with the register and will havecompleted at RI8I' the connection of the rural area to the cord circuit.The operator can then ring the called subscriber and enter intoconversation in the usual manner.

It will be noted that, after the dialing of the subscriberhas beencompleted and the operator lifts her dial key, the ground that had beenapplied to the third wire of the cord circuit, i. e. to the sleeve CL ofthe jack L, is suppressed and the battery is applied again to the sleeveand this again causes relay 33 of the register to come into holdingposition on the above-mentioned circuit. The supervisory lamp of thecord circuit will flash as a result of the ground applied at T4IJI bythe impulsing relay 46 on relay 33 for short-circuiting its highresistance bottom winding. This flicker will continue during the entiretime of sending of the impulses and will end when the register is againreleased.

The operator will now proceed to call the wanted subscriber. For thispurpose she inserts the second plug of the cord circuit that was usedfor calling back the calling subscriber in the jack L associated withthe jack L used for the recall. A battery is connected to the sleeve CLof the plug L and it completes over RM and R33 this circuit of relay 3which pulls up.

The starting circuit of the preselector P is completed via earth, T32,RSI, RM, contact and electromagnet RI of P. V

The wipers of P advance, hunting for a free selector, which will be aselector identical to that of Fig. 2. In the hereunder given descriptionthe explanations will be given as if referring to the diagram of Fig. 2,although in reality this particular selector is in engagement with therural circuit of the calling subscriber as already explained.

When the wipers of P reach the free selector,

the circuit of relay 5 is completed thus: ground,

T3l, series windings of relay 5, Wiper T of P, bank contact and wire tof the free selector, upper winding of relay I4, RI'I2' and battery onthe wire via the register that isassociated with the selector asmentioned in the preceding case. Relay pulls up and completes at Tillthe circuit of the bottom winding of relay 4, which becomes energized.

The operator then receives the same supervisory signals and proceeds toperform the same operations as mentioned in the preceding case for thecall back to the calling subscriber. If the called subscriber belongs toa different rural area from that of the calling subscriber, theprocedure for routing the call is the same as in the preceding case.After disconnection of the register, the subscribers are put incommunication over: rural equipment ER of the called subscriber'scircuit, a selector like the one of Fig. 2, a preselector P, the jack L,the cord circuit, the jack L, a preselector P, a second selector likethe one of Fig. 1, and an equipment ER of the called subscribers ruralcircuit.

' The supervisory signals are given in the supervisory lamps of the'cordcircuit according to one of the methods adopted for rural networks.

Upon termination of the conversation, the operator withdraws the plugsof the cord circuit, the battery is suppressed on the wires 8 and theselectors are released.

If the called subscriber belongs to the same rural area as the callingsubscriber, the following circuit of relay 26 is completed when theregister passes into position 4 (discrimination): ground, resistance R3,T222, wire d, TI 85, wire 01, wiper D of the preselector P, T46, R82,upper winding of relay 8, R62, TI24', wiper DI of the preselector P,wire (II and, in the selector in engagement with the calling subscriber,TI'M, wiper D, wire at multiplied on the selector banks, wiper D of theselector used for calling the wanted subscriber, TI83, common wire d,T223, upper winding of relay 26 and battery.

Relay 8 does not become energized owing to the value of the resistanceR3.

At T26I relay 26 completes its holding circuit on its bottom windingover the ground of T382, and. at T266 it short-circuits the resistanceR3 of the wire 11, at R262 it opens the energization circuit of relay 24before the relay becomes energized; at T263 it completes the circuit ofthe electromagnet X3 over the wiper a at the fourth Working position andthe ground of RZI l. The switch X3 passes to the third working positionfor which the circuit of the electromagnet is again completed across thewiper a and the ground of T264. The switch X3 passes to the sixthworking position.

When the resistance R3 is short-circuited, the intensity of currentbecomes sufficient to cause energization of relay 8 (Fig. 3) over thecircuit that has been mentioned. At T8I it completes its holding circuitover the ground of T124 (relay I2 has pulled up as mentioned whendiscussing the call of the wanted subscriber). At T82 relay 8 completesthe circuit of relay I over the ground of wire d.

Relay I pulls up and at R13 it cuts ofi the battery of CL on the wire sin the direction of the equipment ER of the circuit on which the callback of the calling subscriber has been made, and this results in thepassing of the equipment to the dialing position; at T" it connects thedialing wire A, which comes from the register across the preselector Pand a selecton to the dialing wire that is connected to the equipment ERvia the preselector P and the selector which effects the calling of thewanted subscriber.

When the circuit can receive impulses, the

ground applied to the wire a in the equipment ER causes energization ofrelay 23 over the circuit:

ground across the dialing relay of ER, wire a, wiper A of the selectorused forthe call back of the calling party, T, I74, RIBI, RIGE, wire a1,wiper A1 of the preselector P, TI22, TII, wiper A of the preselector P,TI22, TII, wiper A of the preselector P, wire a, selector used forcalling the wanted subscriber, TI84, common wire a, R24 (Fig. 4) wiper cof X3 at the positions 6 to 10 and, on the one hand, wiper c of XI atthe resting position of relay 23 and, on the other hand, impulse springsZ2, resistance R5 and battery.

The sending of the impulses is then effected in the way mentioned in thepreceding case.

When the register has returned to the resting position after theimpulses have been sent, the selector used for calling the wantedsubscriber assothe wires 01 and t of the preselectorFP'..is suppressedand this causes thefallingeback'of the re- --lays-4'and l (Figr3).

1 the equipment ER of the rural :circuitracrosszthe cpreselector Randthe selector that. isiassociated with it.

dated withthe selector is released asrrnentioned inthe preceding case."Thisiselector hadubeen controlled to the called :direction,:butthe'.connection had not been made; this connection had been -madeimpossible owing to the energizationioftrelay 26 of the register which.had .prevented the excitation of relays 24 of the-register: and [110ithe selector.

Upon the release of the selector, the groundion The conductors oftheplug used forithe call back of the callingpartyare again connected toThe equipmentpasses into the'calling and con- -versation positions .inthe normal manner, and

withthe usual supervision for establishing com-.1

-munication between two subscribers of: one: same area.

When relay ti'fallsbackdFig. 3) ,a supervisory circuit (rapid fiicker)is established by the supervisory lamp of the plug usedfor calling the,

wanted subscriber. This supervisory circuit -warns the operator thatthis plug is to" be withl. drawn: supervisory circuit, wire CL. of plu.L', 1 RM, ground, on the onehand; and low value resistance :R8 andground on the contact of the beater-relay i St, on the other hand.

T83, relatively high resistance 7R1, Land Whenever the operator.ccmpletes'the' connection between two .subscribers of the 'l'ur'aldistrict without calling back the callingsubscribers,

The mode of operation is the-sameas in the preceding case, but, in theequipment of-Fign 3,

:r'elay l2 has not become energized'while relay 6 has become energizedand maintained-pulled up as in the case of thereply to a call from arural subscriber. The circuit of relay 26 of the register used forcalling 1 the 'wantedsubscriber is then completedin the following waytground, resistance R3 (Fig. 4), T222ywire'd'; T|8 6,"wired',

wiper D of the preselector-P',T46, R82; upper winding otrelay8,'T62,---wiper D ofcgwireid *mu1tipled on the banks ofthe-selectors,wiper 'D of the selector used for callinggthe'wanted-subscriber, Tl83',common'wire' d, T223, upper Winding of relay 26 and-battery.

'It is only in this case that the equipmentat :the input endshown-inFig.3 remains in: engage- :-.ment untilthe operatorhas withdrawn the plugsof the cord circuit used for establishing the local connection.

When the operatonestablishes communication between a subscriber outsideof the rural district and a subscriber within the district isheycaniusethe jack G (Fig.1 2) of a-ireaoutg-oing. selector. The general modeof-operation is thecsamelas that described in-thecase of'the :call back-'of-the calling subscriber,- exceptthat theequipmentac-f Fig; 3 does notcome into play and relay I l-(Fig.

' 2) remains inthe resting positionhsince theconnection of theconductors. ofthe two-.strandcord "with the circuit'is 1effected'by';Ri44, Rl'43 and "RMS.

- It-wil1 be noted that after -a---register hasbeen 16 .a'seiz'ed;if-forzany reason (SIOWHESSTOf' the operator *in'setting .up thenumber,: congestion of the-rural .circuits, etc.) the succession ofoperations does not-take; place normally, the already establishedconnections are -released after a certain time (varying from 20 to 40seconds) and the operator 11BC8iVES the busy signal. Forthis'purpose,the 10am lefiectsthe energization' of relay35 on its upper/Winding. .Ifrelay 34has; fallen back-relay :35 completes its holding circuit at T35Ion the 5 ground ofT382. When the cam 2 closes its contact, the circuitof relay 16 of the selector iscom- .i pleted by T352, wire 9', TI 86',upper winding of I6. rAt Tlfil and Tl63 it closes its holding circuitacross the cord circuit, eitheron the wire a or on the wires;atTlfilitconnects the busy signal which is sentto the operator, and at-R|63 it efz-fects the release of the register.

"Inthe device: shown .in Figs. 1- to 4, that has just been'described,:ithas been seen that the choice of the circuit as .well as the,diiferent selections, were effected: automatically by the translater.

The operator does'not'have to worryabout the ruralarea to which thecalled subscriber belongs; it is suflicient for her to use a free jackand to .2 dial the code digits of the subscriber for the connection tobe set up.

Referring to Fig. 6, an explanation will now be given of a device thatpermits simplification of the preceding equipment and that can be usedin small district centrals. Thisdevice which is associated :with .eachoperating position makes it possible to give' the subscribers'of one.district call numbers comprising the same number of figures. The

-'choice of the'circuit is made by the operator while making the callwith the actualnumber of the called subscriber. For example, in the caseof a 'four figure dialing-the choicecorresponding t0 the first digit ismade by the operator by plugging into a certain jack, and the deviceonly registers and translates the hundreds digit. In case the ruralsubscriber is connected to a rural exchange that only-requires a singledigit, the tens digitis absorbed in the deviceand only the units digitis sent to the rural switchboard.

In the illustration-of Fig. 3 it has been -assumed, for example, thatthis translator could serve anetworkcomprising 4,000 numbers, i. e. 40exchanges-or'hundreds, each of the switches XI and X2 havinga capacityof 20 exchanges orhun'dreds.

The hundreds "digit may be translated by 0, '1,

*2 or 3 selections'(connections of the banks Xla',

IXIb', Xl'e' to the-banks:X3a" (I), X30 (III), and X3e' (I) of thesender switch X3). The connections at'theterminalsd and d determinewhether the two last figures (tens digit and units digit) or if only thelast' figure. (units digit) will be :sentdirect over the rural circuit.

' When the operatonhas-inserted the plug of a :cord circuit inthecorresponding jacket the called -subscribers area and shehas receivedthe dialin signal from-the rurallequipmenushe depresses the dial key andrelay 22 (or relay 22' and one of the relays 2|, 23or-24)'becomesenergized by the ground applied-on the-wire .C (or Cl, C2or .The wire C. is multipled onall the dial keys ofcircuits-thatservaior example, the calling numbers of ,the firstthousand, Cl'lon those of the 1 second thousand, C25 .on thoseof thethird thou- 17 lay I: ground, T225, closed contact of the dial CR,resistance RI, winding of I and battery. When relay I' has pulled up,the circuit of relay 2 is completed: ground, T225, RBI, TI2 wiper d ofthe switch X2 at the resting position, wiper g of XI at the restingposition, windin of relay 2 and battery.

The circuit of the dial lamp LC is completed over: ground, T25, R53,lamp LC and battery.

When the dial lamp has lighted up, the operator sets up the hundredsdigit on the dial CR. This dialing will control the switch XI, or X2depending on whether the number is comprised in the 3d or 4th thousandin the example shown in the drawing.

Assuming that the subscribers number is comprised in the third thousand,the circuit of the electromagnet XI, will be completed over: ground,T225, R62, RIZ (at each falling back of relay I whose circuit is open onthe impulse springs of the dial CR), T22, R24I, electromagnet XI, andbattery.

As soon as the dial CR leaves its esting position, the circuit of relay4 is completed: ground, T225, right hand contact of Cr which is closedduring the entire time of dialing, relay 4 and battery. At T4I, relay 4completes over T24 the holding circuit of relay 2 whose holding upcircuit is opened as soon as the wiper g of XI leaves its position ofrest.

Upon termination of the series of impulses, relay 4 falls back, sinceits circuit is opened on the right hand contact of the dial, and at T4Iit opens the circuit of relay 2 which falls back. Ground is applied tothe wipers a, b, c, and d of XI by the circuit: ground, T225, R43, R23I,R242, R2I I and Wipers.

The circuit of the electromagnet X3 is completed by: ground, wiper i ofXI out of its resting position, T22I', R2I, impulse springs I2, R33,R63, wiper h of X3 at its resting position, electromagnet X3 andbattery.

Upon each cut-off of the impulse springs I2, the electromagnet X3advances its wipers by one step. After the first step, the circuit ofthe electromagnet X3 closes over: ground, wiper i of X out of itsresting position, T22I, R2I, impulse springs I2, R33, R63, R82, T224,wiper b of X3.

The bank contacts of the wipers a, b, and c of VI are connected to thebank contacts of the wipers e, c and a'of X3 by means of thedistribution frame Re in such a way as to translate the registeredfigure by 0, 1, 2 or 3 selections.

Let us assume, for example, that the receiver figure is to be translatedby three selections, the first of which consists of a train of twoimpulses, the second by a train of seven impulses and the third by atrain of ten impulses.

In this case the bank contact on which the wiper a of XI" has stoppedwill be connected to the third contact of the bank of the wiper a of X3,the bank contact on which the wiper b of XI has stopped will beconnected to the bank of the wiper c of X3, and the bank contact onwhich the wiper c of XI has stopped will not be connected (sending ofimpulses).

As has been shown, the electromagnet X3 advances its wipers under theaction of the cut-offs of the impulse springs I2.

After the first step of the switchX3, the impulse springs I'2 areconnected to the wire A which is joined to the impulse circuit of therural equipment over: battery, resistance R2, impulse 18 springs II, RBIbanks and wiper f of X3, R52 and wire A.

It can be seen that for each step after the first one by which theswitch X3 advances, an impulse is sent over the wire A, i. e. to theimpulse circuit of the rural equipment.

In the example under consideration, when the wiper a of X3 reaches thethird bank contact, i. e. the second working contact, the followingcircuit of relay 8 is completed: ground on the wiper a of XI over theabove-mentioned circuit, connection at the distribution frame Re, thirdcontact and wiper a of X3, R'I2, series windings of relay 8 and battery.At R8I the impulse circuit is opened and the sending of impulsesterminates. At T83 relay 8 closes its holding circuit on the ground ofT223, and at T82 it completes the automatic rotation circuit of theelectromagnet X3: ground, contact of the electromagnet X3, T82, T224,wiper b of X3 for the first and third quarter turns and wiper d for thesecond and fourth quarter turns, electromagnet X3 and battery.

The electromagnet X3 advances its wipers as far as the sixth position ofthe second quarter turn in which its circuit is open. At this positionrelay 8 is short-circuited by the circuit: ground, T225, wiper b of X3at the sixth position and left hand outlet of the windings of relay 8.The circuit of the electromagnet X3 is then completed over: ground,wiper i of .XI, T22I, R2I, impulse springs I'2, R33, R53, R82, T224,wiper d of X3, electromagnet X3 and battery, and for the sixth position:R84, wiper d of X3, electromagnet X3 and battery. The wipers of X3 thenadvance step by step underthe control of the impulse springs I2. Theobject of this arrangement is to retard the return of the switch X3 toits resting position so as to leave sufficient time for the falling backof the slow relay that is associated with the impulse relay on which thetrain of impulses that have just been sent are received before the saidswitch passes to its last bank contact.

When the wiper b of X3 passes to the last contact of its bank, itcompletes the circuit of relay 3' on the battery connected to. the wireA over the rural equipment: ground, bottom winding of relay 3, wiper bof X3 at the last working position, R52 and wire A. Relay 3' remainspulled up as long as the selectors in the rural exchange are not in aposition to receive the next train of impulses.

At R33 relay 3 makes a cut-ofi in the advance circuit of the switch X3.

As soon as the rural exchange is in a position to receive the next trainof impulses, the battery on the wire A is removed, according to one ofthe known methods, and relay 3 falls back.

The above-mentioned circuit of the electromagnet X3 is again completedand the train of impulses that corresponds to the next figure are sentover the rural circuit in the same way as has been shown for thepreceding figure.

The wiper C of X3 is then engaged with its bank (3d quarter turn). Whenit reaches its eighth bank contact after seven impulses have been sentacross the wiper f of X3, the circuit of relay 8 is again completed. Thesaid relay becomes energized over the circuit: battery, series windingsof 8, R12, wiper e on the seventh working position, wire I at thedistribution frame Re connected to the wire on which the wiper b of XIhas stopped, wiper b, R2I I, R242, R3I', R43, T225 and ground.

Relay 8 stops the sending of impulses and advances the switch X3 asdescribed for the sending of the preceding digit.

The wipers of X3 that are now in engagement with their bank contacts arethose of the foul th quarter turns.

When the wiper b of X3 passes to the 8th position of its bank, relay '1becomes energized over the circuit: ground, T225, bank contact and wiperb of X3, banks and wiper g, relay I and battery.

The relay i" pulls up and at T14 it closes its holding circuit on theground of T225, at T'I2' it connects the circuit of relay 8' to the bankof the wiper e of X3, and at T'II it prepares the circuit of relays 5and 6.

The other successive operations are carried out as indicated above,particularly the .pullling up of relay 3".

When relay 3 falls back, the electromagnet X3" starts again and thethird train of impulses is sent over the rural circuit. Since there isno connection in the iliustrated example between the bank contacts ofthe Wiper c of XI and e of X3, relay 8 only becomes energized when thewiper b or X3 is on the first contact of its bank, i. e. after thesending of 10 impulses, as the impulse circuit is opened when the wiperof X13 has left its bank.

The electromagnet X3 advances its wipers to the resting position of thethird quarter turn. Relay 3' is connected in and the following circuitof relays 3 and 6 is completed over the resting position of the wiper Cof X3: ground, T225, R43, RZBI R242, R21 I, Wiper d of XI and bankcontact connectedeither to terminal D or D, T73, wiper C of X3 in theresting position, relay 5, bottom winding of relay 3 and battery. At R63the advance circuit of the electromagnet X3" is opened.

If the next digit, the tens digit, e. g., is not to be sent, the bankcontact of Wiper d is connected to the terminal D, and the resistanceR4, which is then inserted in the just mentioned circuit of relays 5 and6, prevents energi-zation of relay 5.

If the tens digit is to be sent, the bank contact of wiper dis connectedto the terminal D and relays 5 and 6 become energized in series.

If the tens digit is to'be absorbed when relay 6 becomes energized,while relay 5 remains at rest, the circuit of the lamp of dial LC iscompleted over: ground, T65 and R53. The lamp lights up and the operatorresponds by setting up the tens digit on her dial. Relay 4 becomesenergized as soon as the dial CR leaves its resting position and closesthe circuit of relay 2' over: ground, T41, T64, relay2 and battery. Whenthe dial effects the cut-offs on the dialing springs, relay I beats, butits contact TI I is open at T52 and that of its contact TI2 at RSI.

Upon termination of the train'of impulses, relay fl falls back whenthedialCR has returned to its resting position and before theenergization of relay 2' which is slow? in falling back, andthe'ci'rcuit of relay '5 is completed over: ground, Rel, T23, T62, upperwinding of relay 5" and battery.

'Relay'fi pulls up; at T51" it-completes its holdi'ng "circuit over theground of T225; at T52 it connectsthe bottom winding of re 1ay'3 to wireA a'cr'oss TH; and at T53 it prepares the circuit of'thel'amp o'fth'e'dial LC. Whent'he rural central is ready to receive the last digit,the units digit, relay 3' falls 'back and the circuit of the' iii-3,355

20 lamp LC is completed over: ground, R lI; R3! and T53.

The operator sets up on the dial CR the units digit and everything takesplace in the way described, for the tens digit, except that the impulsestransmitted at RI I via relay I are sent over the wire A of the circuitacross T52,

The testing of the called sub'scribers line is done in any convenientwell-known manner and, when the operator lifts the dial key, thetranslator becomes released, since the circuit of relay 22 is open.

At T225 relay 22 opens the holding circuit of relays 5, 6 and 'I' andcloses the releasing circuit of the rotary switchescircuit XI: ground,wiper 2' out of its resting position, R22I', spring and 'electromagnetXI, battery.

Circuit of X3: ground, interrupter spring of X3 and on the one hand,R226, wiper g of X3 at the resting position, electromagnet X3, batteryand, on the other hand, R224, wiper d on the second and fourth quarterturns or wiper h on the first and third "quarter turns, electromagnet X3and battery,

When the wipers of the switches reach their resting position, thereleasing circuits are opened and the switches stop.

It will be noted that the banks of the wipers a, b, c of XI arerespectively connected to the bank contact of the resting position ofthe wipers a, 0 (across R73) and e of the switch X3 via the wire (1(distribution frame Re) if the train of impulses that corresponds tothis position is not to be sent. This connection causes energization ofrelays 5 and 6 in the way already described for the circuit of the wiperd of Xi, and the trains of impulses that correspond to the last twodigits are sent by the dial over the rural circuit.

If the connection isfma'de by the contact d, the resistance that isinserted in the circuit prevents the energization of relay 5 and thetens digit is absorbed in the already described manner.

It is of course understood that the above embodiments have only beengiven as examples without limitation of the invention thereby, and thatit is possible, without departin from the scope of the invention, toprovide any arrangement of switches or relays that makes it possible toobtain the desired translations, to replace the rotary switches byrelays or vice versa, and to provide other modifications that may benecessary for integrating the devices in any rural systerm.

I claim:

1. In a-telephone exchange system, a plurality of rural exchanges and amain exchange, subscribers lines terminating at said rural exchanges,said lines being designated by numbers havin the same number of digits,automatic selector switches at said .rural and main exchanges over whichcalling and called subscribers lines may be inter-connected, anoperators position at the main exchange, 'a'calIin'g device and aregister operable in accordance with all the digits of the callednumbers "for controllin the establishment of connections betweentwo'subscribers"lines over a certain number 'of selector switches andbetweentwo 'otherlines'ov'er a different number of selector switches.

2. In a telephone exchange'system, aplurality ofruralexchanges-subscribers lines terminating at said exchanges, said 'linesbeing designated 'by numbers having'the same number of digits, automaticswitches at said exchanges for inter-connecting said subscribers lines,a main exchange, an operators position at the main exchange, linefinders for connecting said position to calling lines at the ruralexchanges, a calling device and a translator for controlling theswitches at rural exchanges over a switch at the main exchange, andmeans for operating said translator to control the switches at the ruralexchanges over a line finder.

3. The system according to claim 2 and preselectors for connectingselectors at the main exchange with the operators position.

4. In a telephone exchange system, a plurality of rural exchanges,subscribers lines terminating at said exchanges, a main exchange,selector switches at said exchanges for inter-connecting calling andcalled lines, an operators position at the main exchange, a callingdevice at the operators position, a translator at the main exchangecontrolled by the calling device, nonnumerical switches at the mainexchange for connecting a, rural exchange with the operators position,means operable when the 'called subscriber belongs to the same ruralexchange as the calling subscriber for operating said translator to sendimpulses to a selector t the called rural exchange over a selector atthe main exchange, and means operable when the called subscriber belongsto a diflerent rural exchange from the calling subscriber for sendingimpulses to the called rural exchange via a non-numerical switch.

5. In a telephone exchange system, a plurality of groups of ruralexchanges, subscribers lines terminating at said exchanges, a mainexchange, selector switches at said exchanges for interconnectingcalling and called lines, an operators position at the main exchange,calling device at the operators position, a translator at the mainexchange controlled by the calling device, a pre-selector and a linefinder at the main exchange for connecting a rural exchange with theoperators position, means operable when the called subscriber belongs tothe same rural group as the calling subscriber for operating saidtranslator to send impulses to the rural exchange via a selector at themain exchange, and means operable when the called subscriber belongs toa different rural groupfrom the calling subscriber for sending impulsesto the called rural exchange via a pro-selector and a line finder.

6. In a telephone exchange system, a plurality of groups of ruralexchanges, subscribers lines terminating at said exchanges, a mainexchange, selector switches at said exchanges for interconnectingcalling and called lines, an operators position at the main exchange, acalling device at the operators position, a translator at the mainexchange controlled by the calling device, a preselector and a linefinder at the main exchange for connecting a, rural exchange with theoperators position, means operable when the called subscriber belongs tothe same rural group as the calling subscriber for operating saidtranslator to operate a selector at the main exchange to select thecalled rural group and then to send impulses via the operated selectorto operate selectors for connecting with the called subscriber, andmeans operable when the called subscriber belongs to a difierent ruralgroup from the calling subscriber for operating said translator tooperate a selector at the main exchange to select the called rural groupand then to send impulses to the called rural exchange via a preselectorand a line finder.

7. In a telephone system, a plurality of groups of rural exchanges,lines terminating at said exchanges, selectors at said exchanges forinterconnecting calling and called lines, a main exchange, an operatorsposition at the main exchange, a translator, a calling device at theoperators position for operating the translator in accordance with thefirst digit of the called number to select the group to which the calledrural subscriber belongs, and means for operating the translator forsending impulses to control selectors'at the called rural exchange.

8. In a telephone exchange system, a plurality of rural exchanges,subscribers lines terminating thereat, selector switches at saidexchanges for inter-connecting calling and called lines, a mainexchange, an operators position thereat,

a translator at the main exchange, a, selector switch at the mainexchange, a calling device at the'operators position for operating saidtranslator in accordance with the digits of the called number, means.controlled by the translator for operating the selector switch at themain exchange and the selector switches at the called rural exchange,and means in said translator for absorbing certain digits of the callednumber.

9. ma telephone exchange system, a, plurality of rural exchanges, a,central exchange comprising an operators position, the numericaldesignations of all the lines terminating at the rural exchanges beingcomposed of the same number of digits, trunk lines between saidexchanges, automatic switches at said rural exchanges for establishingconnections with subscribers lines, numerical and non-numerical switchesat the main exchange, connections from each numerical switch to theoperators position and to the nonnumerical switches in multiple,connections from the position to the non-numerical switches, a

translator arranged to be connected with the numerical switches, a firstand a second rural circuit link, multiple connections from the firstcircuit link to the numerical and the first nonnumerical switch andmultiple connections from the second link to the numerical switches,means responsive to the initiation of a call by a rural jsubscriber foroperating the first non-numerical switch to extend the calling line overthe first rural circuit link and the first non-numerical switch to theoperators position, means controlled by the operator for establishing aconnection with a called rural subscriber over a numerical switch, andover a non-numerical and numerical switch in series, the last-mentionedmeans including a calling device operable in accordance with thenumericaldesignations of the called rural line,

means in the translator for registering the digits sent out by thecalling device, means controlled by the translator for operating saidnumerical switch to select a rural circuit link depending on thelocation of the called subscriber and for controlling the operation ofthe switches at the called rural exchange to select the calledsubscriber, means controlled by the translator when the calledsubscriber is located within the same exchange or group of exchanges asthe calling subscriber for sending impulses over the operatednon-numerical switches and the first rural circuit link for operatingthe switches at the called rural exchange to connect with the calledsubscriber, and means operative upon the establishment of the connectionbetween the calling and called rural subscribers for releasing thetranslator and all the switches at the main exchange.

10. In a. telephone exchange system, a plurality 23 of group o'f'rura'lexchanges, a central exchange comprising an operators position, other anchanges, subscribers terminating at "said exchanges, the numericaldesignations of all the lines terminating at the rural exchanges-beingcomposed of the same number zit-digits, trunk iines between saidexchanges, automatic'switches at said rural exchanges 'forestablishingconnections with subscribers line's, selector, finder and pre-selectorswitches at the main exchange; said position having first means "overwhich connections from said other exchanges to the rural ex chan'ges canbe established, second'means over which connections between ruralsubscribers can be established, connections from each selector to afirstmea'ns calling jack and to the pro-selectors, connections from eachsecond means to a -brie-selector, connections from certain second meansto a finder, a translator arranged "to be connected with the selectors,a first and a second rural circuit link, connections from the firstcir-- cuit link to th finders and the selectors, connections from thesecond linkto the selectors, means responsive to the initiation of acall by a rural subscriber for operating said finder switch to extendthe calling line over the first rural circuit link and a finder to theoperators position over the second means, means controlled by theoperator .for establishing a connection with a called rural subscriberover a first means and the associated selector, and over asecondmeanathe associated pro-selector, and a selector, the lastmentionedmeans including a calling device operable in accordance with thenumerical designations of the called rural line, means in the translatorfor registering the digits sent out by the calling device, meancontrolled by the translator for operating said selector to select arural circuit link depending on the location of the called subscriberand for controlling the operation of the switches at the called ruralexchange to select the called subscriber, means controlled by thetranslator when the called subscriber is located within the sameexchange or groupof exchanges as the calling subscriber for sendingimpulses over the operated pro-selector, the operators position, thefinder and the first rural circuit link for operating the switches atthe called frura'l exchange to connect with 'the'called subscriber, andmeans operative upon the'establishment of the connection between thecallingand called rural subscribers for releasing the translator and allthe switches at the main exchange.

11. In a telephone exchange system, a plurality of groups of ruralexchanges, a central exchange comprising an operators'position, otherexchanges, subscribers lines terminating at said exchanges, thenumerical designations of all the lines terminating at the ruralexchanges being composed of the same number of digits, trunk linesbetween said exchanges, automatic switches at said rural exchanges forestablishing connections with subscribers lines, selector, finder andpre-selector switches at the main exchange, each having a terminal bankand wipers cooperating therewith, said position having calling jacksover which connections from said other-exchanges to the'irura-lexchanges can be established, and intar-rural paired'answering andconnecting ,jacks over which connection with rural subscribers can beestablished, connect-ions from the Wipers of each selector to a callingjack and to the terminal'banks of the pre-selectors in multiple,connections from'ea-ch connecting jack to the wipers of a pre-selector,multiple connections from each answering .jack to the wipers of a,pre-selector and a finder, a translator arranged .to be connected withthe wipers of the selectors, a first and a second rural circuit link,multiple connections froirn the first circuit link to the terminal banksof the finder and the selectors and multiple connetctions from thesecond link to the selectors, means responsive to the initiation of acall by a rural subscriber for operating said finder switch to extendthe calling line over the first rural circult :link and a finder to theassociated answering jack, imeans controlled by the operator iorestablishing a connection with a called rural subscriber over a callingjack and the associated selector, and over an answering or a connectingjack, the associated pre-selector, and 'a selector, the last-mentionedmeans including a calling device operable .in accordance with thenumerical designations of the-calledrural line, means in the transiatorfor registering the digits sent out by the calling device,meanscontrolled by the translator -foroperating said selector to select arural circuit link depending on the location of the called subscriberand 'for controlling the opera- :tion of the switches at the calledrural exchange to select the called subscriber, means controlled by thetranslator when the called subscriber is located within the sameexchange or group of ,exchanges as the calling subscriber for sendingimpulses over the operated gore-selector, the associated jack, the.finderand the first rural circuit link for operating the switches atthe .called rural exchange to connect with the called subscriber, meansoperative upon the establishment of the connection between the callingand called rural subscribers for releasing the translator and all theswitches at the main exchange, means controlled by the operator forringing a subscriber over a circuit including a connecting jack and theassociated pre-selector and selector, and means controlled by theoperator for ringing a rural subscriber over a connection including ananswering jack and the associated pre-selector and selector.

.FERNAND P. GOHOREL.

REFERENCES CITED The a'ollowing vreferences are of record in the ule-ofthis patent:

UNITED "STATES PATENTS Number Name Date "1,788,411 :Powell Jan. v13,1931 3,105,;0-12 Saunders Jan. 11, 1938 2,158,945 Peterson May 16, 19392,145,127 Peterson J an. 24, 1939 4 5783309 Currier Mar. 30,1926

